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erat Soy 
1897 | THE CURVATURE OF ROOTS 337 
TANGENTIAL LONGITUDINAL SECTION. 
| 36 48 45 38.5| 44.8] 26.7] 39 34 27 26.6 
Concave te ess ib a7 20:7} 207) 24 27 28 24 
An examination of the sections from 
which the above measurements were made 
reveals the fact that the distance from the 
apex of the growing point to the cross sec- 
tion exhibiting the shortest radius of curva- 
ture is 2™™; from the apex to the beginning 
of the region of curvature 1.5™™. At this 
point the root is 1™ in diameter. The 
epidermal cells of the concave side appear 
densely granular. The greater number of 
the nuclei in the cortex of the concave side 
appear to lie on the peripheral side of the 
cells, though not always substantiated by 
actual count. The axial diameter of the 
Cortical cells is smaller than that of the 
Convex side, though no great compression A 
has been exerted in this plane, since no fold- Fic. 5. Longitu- 
ings were observable in the longitudinal dinal sections through 
walls. The radial cross walls were of a con~ “Vt. POO = * 
tour indicative of compression in an axial re Re 
direction and exhibited a wavy or undulat- — area? pares 
. | convex side; Y 
ing outline ( fig. 5). cave side (see tables 
I-IV). 
TABLE V. 
Median longitudinal section of root of Zea mais twenty hours after exci- 
tation began, and after a curvature of 105° had been effected. 
MEASUREMENTS OF LENGTH OF CELLS OF CONVEX SIDE. 
ical Basal a 
(Ep) ~ 40 50 6o.* 120 55 “- ae <= 69.2 
25 
ew me se 
